Laserfiche WebLink
EXHIBIT G <br /> Water Information <br /> In this area, shallow groundwater has historically been located roughly 3 to 6 feet below the <br /> existing ground level. The movement of groundwater is generally south to north at this location. <br /> It is anticipated that the liners will result in a small increase to the shallow groundwater levels on <br /> the south side of the reservoirs (known as groundwater mounding), with a small decrease in <br /> shallow groundwater levels on the north side (known as groundwater shadowing). A <br /> groundwater model was prepared to estimate the magnitude of the anticipated mounding and <br /> shadowing. A report on the model is attached, and contours of the mounding and shadowing <br /> impacts are displayed on the attached figure. <br /> The groundwater model estimates that the maximum amount of mounding would be <br /> approximately four feet; mounding of this magnitude will be limited to the area between the two <br /> reservoirs on the south side. The nearest existing well (not owned by Martin Marietta)which <br /> will be most impacted by groundwater mounding will be a monitoring well owned by Capital <br /> Pacific Homes under Permit No. 43937-DW. The amount of mounding at this well is expected <br /> to be less than half a foot, which is unlikely to impact the usability of this well. The nearest <br /> structure (not owned by Martin Marietta)which will be most impacted by groundwater <br /> mounding will be the residence at 2719 Weld County Road 201/2, owned by Michael&Elizabeth <br /> Gerhardt. The amount of mounding at this structure is expected to be between three and four <br /> feet, which could potentially cause flooding issues of low areas at the residence such as the <br /> basement(if one exists). The section of liner nearest the Gerhardt's house was completed in <br /> March 2016, and to date there have been no complaints of flooding. <br /> The groundwater model estimated that the maximum amount of shadowing would be <br /> approximately two feet; shadowing of this magnitude will be limited to the area immediately <br /> adjacent to the reservoirs on the north side. The nearest well (not owned by Martin Marietta) <br /> which will be impacted by groundwater shadowing will be an irrigation well owned by Barrett <br /> Ward under Permit No. 668-WCB. The amount of shadowing at this well is expected to be <br /> between one and 1.5 feet. According to information on this well obtained from the Colorado <br /> Division of Water Resources,Mr.Ward's well is 25 feet deep and had a static water level of six <br /> feet when it was constructed.2 Given the depth of the well and generally high groundwater level <br /> in the area, it is unlikely that shadowing caused by the lined reservoirs will significantly impact <br /> the usability of this well. <br /> Martin Marietta operates three active monitoring wells located around the periphery of the <br /> Duckworth Pit. Martin Marietta has collected data on these wells prior to the beginning of <br /> mining operations and while mining was occurring. Martin Marietta will continue to collect data <br /> from these monitoring wells for a period of two years following completion of the liner to <br /> compare actual groundwater level changes with the changes anticipated by the groundwater <br /> model. Given that the liner was completed in March 2016,Martin Marietta's groundwater <br /> monitoring obligation will cease in March 2018. <br /> 2 httl2://www.dwr.state.co.us[WellPermitSearch,accessed November 18,2016. <br /> Duckworth Pit <br /> DRMS 112 Pennit Amendment <br /> Page 8 <br />